Angiotensin II receptor antagonists and calcium channel antagonists are presently widely used as drugs to treat or prevent hypertension, heart disease, or the like. Angiotensin II receptor antagonists, which are renin-angiotensin inhibitors, are particularly effective against renin-dependent hypertension, and they demonstrate a protective action against cardiovascular or renal damage. Calcium channel antagonists have a natriuretic action in addition to a vasodilating action, and they are also effective against body fluid retention (renin-independent) hypertension. It is therefore expected that the combined use of an angiotensin II receptor antagonist and a calcium channel antagonist would yield a calcium channel antagonist action and a secondary natriuretic action in vascular smooth muscles due to the calcium channel antagonist in addition to the inhibitory effect on the renin-angiotensin system due to the angiotensin II receptor antagonist, which would make it possible to inhibit multiple hypertension factors simultaneously, and that this combination would demonstrate stable and sufficient therapeutic or preventative effects against hypertension, regardless of the cause of the disease.
Thiazide diuretics are also widely used as drugs to treat or prevent hypertension, heart disease, or the like. Their diuretic effect makes thiazide diuretics effective for the treatment of hypertension. It is therefore expected that the combined use of an angiotensin II receptor antagonist and a thiazide diuretic would make it possible to inhibit multiple hypertension factors simultaneously due to the diuretic action of the thiazide diuretic in addition to the inhibitory effect on the renin-angiotensin system due to the angiotensin II receptor antagonist, and that this combination would demonstrate stable and sufficient therapeutic or preventative effects against hypertension, regardless of the cause of the disease.
(5-Methyl-2-oxo-1,3-dioxolan-4-yl)methyl 4-(1-hydroxy-1-methylethyl)-2-propyl-1-[2′-(1H-tetrazol-5-yl)biphenyl-4-ylmethyl]imidazole-5-carboxylate (called olmesartan medoxomil hereinafter) is an excellent angiotensin II receptor antagonist, and its usefulness as a drug for treating or preventing hypertension, heart disease, and the like is well known (Japanese Patent 2082519, U.S. Pat. No. 5,616,599).

Olmesartan medoxomil is marketed as Olmetec (registered trademark) tablets or Benicar®, and these contain 5 mg, 10 mg, 20 mg, or 40 mg of olmesartan medoxomil as active ingredient and low-substituted hydroxypropyl cellulose, hydroxypropyl cellulose, microcrystalline cellulose, lactose, and magnesium stearate as excipients.
3-Ethyl-5-methyl-(±)-2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methylpyridine-3,5-dicarboxylate (called amlodipine hereinafter) is a well-known compound which is an excellent calcium channel antagonist and is useful as a drug for treating or preventing hypertension, heart disease, and the like.

Amlodipine is marketed as Norvasc (registered trademark) tablets, and it contains 3.47 mg or 6.93 mg of amlodipine besylate as active ingredient (2.5 mg or 5 mg of amlodipine) and microcrystalline cellulose, anhydrous calcium hydrogen phosphate, carboxymethyl starch sodium, magnesium stearate, hypromellose, titanium oxide, talc, and carnauba wax as excipients.
Further, 6-chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide-1,1-dioxide (called hydrochlorothiazide hereinafter) is a compound that is well known as an excellent thiazide diuretic, and it is described, for example, in U.S. Pat. No. 3,025,292.

Drugs which combine olmesartan medoxomil and amlodipine (pamphlet of International Patent Publication WO 2004/067003) and drugs which combine olmesartan medoxomil and hydrochlorothiazide (pamphlet of International Patent Publication WO 2002/041890) are known in the prior art, but there is no known solid dosage form such as that of the present invention containing olmesartan medoxomil and amlodipine having improved dissolution properties as a result of the further inclusion of excipients containing calcium. Moreover, there is no known solid dosage form such as that of the present invention containing olmesartan medoxomil, amlodipine and hydrochlorothiazide having improved dissolution properties as a result of the further inclusion of excipients containing calcium.    [Patent Document 1] Japanese Patent 2082519 (U.S. Pat. No. 5,616,599)    [Patent Document 2] Japanese Patent 1401088 (U.S. Pat. No. 4,572,909)    [Patent Document 3] U.S. Pat. No. 3,025,292    [Patent Document 4] Pamphlet of International Patent Publication WO 2004/067003    [Patent Document 5] Pamphlet of International Patent Publication WO 2002/041890